Road planing machines

ABSTRACT

A road planing machine having a cutter assembly and a collecting and elevating assembly, the cutter assembly comprising a series of side-by-side rotary cutter wheels arranged transversely of the direction of movement of the machine in use, the cutter wheels being interlocked for rotation in unison and each being driven by an individual hydraulic motor supplied from a common pressure source. The machine may include a heating unit mounted forwardly of the cutter assembly, the heating unit preferably being gas fired and the gas supply pipes for the heater and oil return pipes from the cutter motors effecting a heat exchange. Air may be drawn from the heater and passed over it to the front of the machine to be directed downwards on to the road to pre-heat the latter.

United States Patent 1191 Steiner ROAD PLANING MACHINES [75] Inventor: Hubert Steiner, Stoke-On-Trent,

England [73] Assignee: H. Steiner Limited, Staffordshire,

England [22] Filed: July 21, 1972 [21] Appl. No.: 273,890

[30] Foreign Application Priority Data July 23, 1971 Great Britain 34591/71 [52] US. Cl 404/90, 404/95, 299/41 [51] Int. Cl. E0lc 23/12 [58] Field of Search 404/83, 84, 85, 101, 104, 404/105, 106, 95, 91, 113; 299/41; 173/24 [56] References Cited UNITED STATES PATENTS 2,747,475 5/1956 West 404/91 2,769,626 11/1956 Becker... 299/41 3,055,280 9/1962 Neville 404/95 3,096,696 7/1963 Reisser 404/95 3,148,917 9/1964 Thompson 299/41 X July 23, 1974 Primary Examiner-Nile C. Byers, Jr. 7 Attorney, Agent, or Firm Alan H. Levine; Breitenfeld & Levine [5 7 ABSTRACT A road planing machine having a cutter assembly and a collecting and elevating assembly, the cutter assembly comprising a series of side-by-side rotary cutter wheels arranged transversely of the direction of movement of the machine in use, the cutter wheels being interlocked for rotation in unison and each being driven by an individual hydraulic motor supplied from a common pressure source. The machine may include a heating unit mounted forwardly of the cutter assembly, the heating unit preferably being gas fired and the gas supply pipes forthe heater and oil return pipes from the cutter motors effecting a heat exchange. Air maybe drawn from the heater and passed over it to the front of the machine to be directed downwards on to the road to pre-heat the latter.

23 Claims, 10 Drawing Figures PATENTEB JUL-231914 SHEET 1 [1F 9 PATENTEDJULZEHSH SHEET 5 or 9 I I f I I! VI /A/ The invention relates to machines for use in the resurfacing of roadways and particularly to machines of the kind generally referred to as planing machines.

Road planing machines generally comprise wheeled or tracked vehicles (usually self-propelled) having a forwardly-mounted heating unit behind which is located a rotating cutter assembly adapted to remove the heated road surface to a desired depth after which the dislodged and broken down surfacing material is directed by guides to the lower end of an elevator which lifts the material clear of the road surface and deposits it into a suitable wagon or the like towed by, folowing behind or forming part of the planing machine. In some instances the heating unit may be omitted to produce a cold rather than a hot planing machine.

The present invention incorporates a number of novel aspects. Thus according to one aspect of the invention there is provided a road planing machine having a cutter assembly and a collecting and elevating assembly, the cutter assembly comprising a series ofsideby-side, generally horizontal, rotary cutter wheels arranged transversely of the direction of movement of the machine in use, the cutter wheels being interlocked for 2 FIG. 7 is a diagram of the hydraulic transmission system of the machine; and

FIG. 8 is a hydraulic circuit diagram showing certain fail-safe features.

The machine to be described with reference to the drawings is a hot planing machine having a heating unit for softening the road surface prior to cutting. It will be appreciated however that a cold planing machine could be similarly constructed and would differ only in the omission of the heater and its associated equipment.

Referring to the drawings, the machine includes a main frame or chassis 5 supported towards the rear by main driving wheels 6 and at the front by a steerable wheel assembly 7. Mounted towards the rear of the frame is an internal combustion engine 8 coupled to hydraulic pumps 9 and 10. Hydraulic fluid is drawn from rotation in unison and each being driven by an individual fluid motor supplied from a common pressure fluid source. This cold planing machine may be converted to a hot planing machine by the addition of a forwardly-mounted heating unit.

According to a further aspect of theinvention there is provided a road planing machine comprising a heating unit, a cutter assembly and a collecting and elevating assembly, the heating unit being a gas-fired, infrared heater and the cutter assembly being hydrulically driven, the gas supply pipes for the heater and the oil return pipes from the cutter assembly being arranged to effect a heat exchange whereby the gas supply is heated and the hydraulic fluid cooled. The gas is preferably supplied from a series of individual supply bottles mounted at a suitable location on the machine and pre-heated by means of heater or heaters.

Accordng to a further aspect of the invention there I is provided a road planing machine comprising a heating unit, a cutter assembly and a collecting and elevating assembly, and including fan means arranged to draw in air and deliver same over the heating unit to an outlet at the forward end thereof, whereby to pre-heat the road surface.

It will be appreciated that these various novel aspects of the invention may all be incorporated in one machine or may be utilised individually in machines otherwise of standard construction.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which:

FIG. 1 and 1A is a plan view of a road planing machine according to the invention;

FIG. 2 and 2A is a side elevation of the machine shown in FIG. 1;

FIG. 3 is an enlarged cross-section through a cutting head;

FIG. 4 is an enlarged plan view of two adjacent cutting heads;

FIG. 5 is an enlarged vertical cross-section through a heat-exchanger unit;

FIG. 6 is a plan view of the unit shown in FIG. 5;

a two-part reservoir 11 and delivered by the pumps to each of a series of hydraulic motors driving rotary cutters which will be described in greater detail hereafter. The rotary cutters are arranged transversely of the frame of the machine between a road heating unit 12 and a pair of guide vanes 13, the latter converging rearwardly to an elevator assembly 14. Theheating unit is of the infra-red type fired by gas supplied from a series of bottles 15 mounted in cradles 16 at opposite sides of the main frame towards the rear of the latter.

The cutter assembly consists of four transversely disposed cutter units one of which is illustrated in FIG. 3. Each unit consists of a main carrier tube 20 secured to the chassis 5 and within which is slidably supported an inner tube 21 carrying a hydraulic motor 22 and gearbox 23 having an output shaft 24 keyed at 25 to a drive tube 26 to the lower end of which a rotary cutter disc 27 is secured. The lower surface of the cutter disc is provided with diamond cutting tools 28 and the upper surface carries a series of circumferentially-spaced vertical posts or tubes 29 rigidly held in position by annular locating plates 30 secured to their upper ends.

The periphery of the cutter is of toothed or lobed form and the tubes 29 are mounted one on each tooth or lobe. The inter-tooth spaces engage with corresponding teeth or lobes formed on adjacent cutter discs as best seen in FIG. 4 so that the entire series of discs are interengaged in the fashion of gear wheels.

The cutter units may each be raised either individually or in unison by means of individual hydraulic rams 31 (FIG. 3) anchored at their upper ends to the chassis 5. The rams are pivotally connected to brackets 31B fastened to the inner tubes 21 and sliding in slots (not shown) in the outer tubes 20. In this way the cutter units may be lifted clear of the ground for transport purposes when the machine is not in use. An alternative position for the rams is shown in broken lines at 31A. The converging guide members 13 and the lower end of the elevator assembly 14 are also arranged to be lifted clear of the ground in a similar fashion.

As indicated, the heating unit is of the infrared type and may be of known construction. It is energised by a gas supply from the bottles 15, and in order to avoid problems in freezing of the gas through over-rapid withdrawal from the bottles, andto cool the oil in the hydraulic circuitry of the machine, a heat exchanger is incorporated. This is shown in FIGS. 5 and 6 and comprises an oil reservoir 32 fitted with inlet and outlet pipes 33, 34 and internal baffles 35. Two sections 36A, 36B of the gas supply pipe leading from the bottles 15 to the heating unit, are interconnected by a series of heat transfer pipes 37 passing through the reservoir 32 so that the gas'supply is heated by the oil and the latter cooled. This heat exchange arrangement produces a heat rising from the unit 12 and is directed on to the ground ahead of the unit to pre-heat the road surface. A second duct 47 (FIG. 2) is also taken from the fan 43 and directs hot air through hollow box members of the chassis to the rear of the machine where it is delivered into the gas bottle cradles 16 through outlets 48. This prevents freezing of the bottles in cold weather. When in use the machine may be driven forwards at low speeds by a hydraulic drive mechanism, but also includes a mechanical transmission arrangement enabling forward travel of the machine at higher speeds during movement from-one location to another. The

drive and transmission arrangement is shown in "FIG. 7 and includes a transfer box 49, connected by propshafts 50 and 51 to an engine 52 and rear axle assembly 53. A conventional manually operated change-speed gearbox 59 is interposed between the engine and the propshaft 50. The transfer box also has an auxiliary output shaft 54 coupled to a hydraulic pump 55 and an auxiliary input 56 driven by a hydraulic motor 57 supplied with hydraulic fluid from the pump 55 under control of a valve. assembly 58.

The relatively high speeds for road travel are obtained by the engine driving the rear axle by way of the propshafts 50 and 52, gear changes being provided by the box 59 in the normal way. When low speeds for working are required the transfer box is adjusted to connect shaft 50 to the auxiliary output 54 and shaft 51 to the auxiliary input 56. The pump 55 is thus driven by the engine and supplies fluid to drive the motor 57 and rear axle. This hydraulic drive enables the very low creeping speeds which are required for effective treatment of road surfaces to be achieved.

The hydraulic equipment of the machine is controlled from a main valve block 60 in FIG. 1. This block may be duplicated at the opposite side of the machine by means of mechanical linkages. Part of the hydraulic circuitry is shown in FIG. 8. Fluid is drawn by the engine driven pumps 9 and from the reservoir 11 and supplied via lines 61 and 62 to the cutter motors 22. The lines 61 and 62 incorporate pressure relief valves 61A and 62A which form part of a safety circuit which stops the macine if any one of the cutters strikes an obstruction (for example a manhole) which it cannot dislodge. In such event a back pressure builds up in lines 61 and 62 resulting in opening of the valves 61A and 62A and diversion of fluid along line 63 to a ram 64. Connected to the outlet side of ram 64 is another pressure relief valve 65 set at a higher pressure than the valves 61A and 62A. The difference in pressure causes the ram 64 to operate and disengage the transmission clutch thereby stopping the machine..Before the machine can be restarted the pressure in line 63 must be released by means of a manual valve 66, thus releasing ram 64 and engaging the clutch. A cut-out switch is also incorporated to stop the machine if the heat output from the heating unit is too low for satisfactory operation.

In operation, the cutter assembly, heating unit, guide members 13 and lower end of the elevator 14 are lowered into their operative positions, and after allowing sufficient time for the heating unit to reach the desired temperature, the machine is driven slowly forwards with the cutter discs rotating in unison. The cutter discs are arranged to remove the road surface to a desired depth of say one inch, and as the machine moves forwards the dislodged material is drawn together by the guide members and lifted by the elevator to be positioned in a suitable receptacle drawn behind the machine. The use of individual hydraulic motors operating a series of relatively small diameter cutter discs enables the necessary cutting effort to be achieved with a low power input compared with previous machines utilising mechanically driven large diameter cutters. Moreover the inter-gearing of the cutters results in a transfer of effort between them, should one cutter encounter particularly hard resistance or an obstruction. The intergearing also results in rotation of a cutter even though its drive motor ceases to function properly due to a fault.

In order that the'machine need not be stopped when the Waggon or other receptacle into which the material is discharged becomes full, a surge hopper is provided at the upper end of the elevator 14. A cover or door 71 for the hopper is controlled by means of linkages connected to a lever placed conveniently to the operator, and when the door is closed the material from the elevator is collected in the hopper. After the waggon has been changed the door 71 is opened and the material is discharged into the empty wagon.

The machine described and illustrated is only one embodiment of the invention and many modifications and variations may be effected. For example, the machine could be provided with more than one transverse bank of cutting heads and these banks could be arranged at different levels and widths so that, for example, the forward bank removed the road surface to a depth of one inch and the rearward bank to a depth of a further one inch, producing a total cutting depth of 2 inches. The number of cutting heads provided and the diameter of the cutting discs may also be varied and the machine may be provided with different forms of heating unit or different arrangements for collecting the dislodged road surfacing material. The gas supply for the heating unit, where provided, may be obtained from a storage tank or tanks instead of a series of individual bottles.

In a further modification the controls may be of a portable nature, and may be positioned on either side of the vehicle. Alternatively, the steering wheel and instrument panel, together with the drivers seat and controls may be mounted on a track, enabling the operator to slide along the width of the vehicle to the desired position. In a further modification extension controls could be provided enabling the machine to be controlled by an operator located on the ground alongside the machine.

Moreover it should be appreciated that while the invention has been described primarily withreference to a machine which produces a hot cut by virtue of the provision of the forward heating unit, theiinvention is also applicable to machines producing a cold" cut, that is, not provided with a heating unit. The arrangement of two cutter banks disposed at difierent levels previously referred to is particularly suitable for use in connection with cold cutting machines. A cold cutting machine would generally require a greater power input to the cutters than is required for a corresponding hot cutting machine.

The low-speed hydraulic drive described could be replaced by some other form of creep speed mechanism; for example, individual hydraulic motors could be fitted to the road wheels of the machine.

I claim:

1. A road planing machine having a frame provided with ground-engaging wheels, a cutter assembly comprising a series of side-by-side, generally horizontal rotary cutter wheels mounted on the frame and extending transversely across the frame, the cutter wheels being of lobed or toothed form and interengaging with one another in the manner of gear wheels, means acting between each cutter wheel and said frame for effecting independent vertical movement of each cutter wheel with respect to adjacent cutter wheels while maintaining the wheels in engagement with one another, and a collecting and elevating assembly mounted on said frame rearwardly of the cutter assembly relative to the forward direction of movement of the machine in use.

2. A road planning machine according to claiml wherein each said cutter wheel is provided with a series of upstanding posts mounted on one each of said lobes or teeth, the posts acting as vertically elongated teeth which remain operatively engaged with one another on relative vertical movement of the associated cutter wheels.

3. A road planning machine according to claim 1 including a heating unit mounted forwardly of said cutter assembly, relative to the forward direction of movement of the machine in use.

4. A road planing machine according to claim 3 wherein said heating unit is a gas-fired infra-red heater.

5. A road planing machine according to claim 4 including hydraulic drive means for said cutter assembly, hydraulic fluid supply and return pipes coupled to said hydraulic drive means for the cutter assembly, gas supply pipes connected to said heating unit, and a heat exchanger mounted on the machine and through which said hydraulic fluid return pipes and said gas supply pipes pass whereby to effect a heat exchange to heat the gas supply and cool the hydraulic fluid.

6. A road planing machine according to claim 4 wherein gas for said heating unit is drawn from a series of individual bottles mounted on the machine.

7. A road planing machine according to claim 6 wherein said gas supply bottles are pre-heated by means of one or more heaters mounted on the machine adjacent to the gas supply bottles.

8. A road planing machine according to claim 7 including duct means extending between said heating unit and said gas supply bottles and having an outlet directed towards said gas supply bottles to direct hot air from the heating unit on to the gas supply bottles to pre-heat said bottles.

9. A road planing machine according to claim 3 including duct means extending over said heating unit and having an outlet disposed at the forward end of said heating unit relative to the forward direction of movement of the machine in use, and fan means arranged to deliver air from said heating unit through said duct means to said outlet, said outlet being directed downwardly so as to direct said air on to the road surface ahead of the heating unit to pre-heat said surface.

10. A road planing machine according to claim 3 including means arranged between said frame and said heating unit'for raising said heating unit clear of the ground for transport purposes.

11. A road planing machine to claim toclaim 3 including drive means operable to effect forward movement of the machine, means operable to interrupt said drive means to stop movement of the machine,'sensing apparatus coupled to said heating unit and operable to give a signal in the event of the heat output from said unit falling below a pre-determined level, and control means operable in response to said signal to actuate said means for interrupting the drive means.

12. A road planing machine according to claim 1 including rearwardly converging guide members mounted between said cutter assembly and said elevator to draw together material removed from the road surface by the cutters for lifting by said elevator.

13. A road planing machine according to claim 12 wherein said guide members and said elevator are adjustably mounted for movement to a position clear of the road surface for transport purposes.

14. A road planing machine according to claim 1 including a hydraulic drive mechanism operatively'connectable to said ground-engageing wheels of the machine to provide infinitely variable low speed creeping movement of the machine during operation.

15. A road planing machine according to claim 14 including in addition a mechanical drive mounted on said frame and operatively connectable to said groundengaging wheels to propel the machine when not in use, and control means operable to selectively couple either said hydraulic or said mechanical drive to the groundengaging wheels of the machine as required.

16. A road planing machine according to claim 14 including means for disengaging said hydraulic drive mechanism in the event of any cutter of the cutter assembly striking an obstruction.

17. A road planing machine according to claim 1 wherein said cutter assembly includes more than one series of transversely arranged cutter wheels, the successive series being disposed at different cutting depths relative to the road surface.

18. A road planing machine according to claim 1 including a main control station movably mounted on the machine between alternative operating positions at opposite sides of the machine.

19. A road planing machine according to claim 1 including a main control station slidably mounted on a track extending transversely of the machine.

20. A road planing machine according to claim 1 including a main control station, and extension controls coupled to said main control station and disposed at a low level at one side of the machine.

21. A road planing machine according to claim 1 including an individual fluid-operated motor operatively coupled to each of said cutter wheels and hydraulic fluid supply and return pipes connecting each of said motors to a common pressure fluid source mounted on the machine.

22. A road planing machine having a frame provided with ground-engaging wheels, a cutter assembly mounted on the frame, a heating unit mounted on the face ahead of the heating unit to pre:heat said surface.

23. A road planing machine according to claim 22 wherein said fan means is arranged to draw in said air from said heating unit. 

1. A road planing machine having a frame provided with groundengaging wheels, a cutter assembly comprising a series of sideby-side, generally horizonTal rotary cutter wheels mounted on the frame and extending transversely across the frame, the cutter wheels being of lobed or toothed form and interengaging with one another in the manner of gear wheels, means acting between each cutter wheel and said frame for effecting independent vertical movement of each cutter wheel with respect to adjacent cutter wheels while maintaining the wheels in engagement with one another, and a collecting and elevating assembly mounted on said frame rearwardly of the cutter assembly relative to the forward direction of movement of the machine in use.
 2. A road planning machine according to claim 1 wherein each said cutter wheel is provided with a series of upstanding posts mounted on one each of said lobes or teeth, the posts acting as vertically elongated teeth which remain operatively engaged with one another on relative vertical movement of the associated cutter wheels.
 3. A road planning machine according to claim 1 including a heating unit mounted forwardly of said cutter assembly, relative to the forward direction of movement of the machine in use.
 4. A road planing machine according to claim 3 wherein said heating unit is a gas-fired infra-red heater.
 5. A road planing machine according to claim 4 including hydraulic drive means for said cutter assembly, hydraulic fluid supply and return pipes coupled to said hydraulic drive means for the cutter assembly, gas supply pipes connected to said heating unit, and a heat exchanger mounted on the machine and through which said hydraulic fluid return pipes and said gas supply pipes pass whereby to effect a heat exchange to heat the gas supply and cool the hydraulic fluid.
 6. A road planing machine according to claim 4 wherein gas for said heating unit is drawn from a series of individual bottles mounted on the machine.
 7. A road planing machine according to claim 6 wherein said gas supply bottles are pre-heated by means of one or more heaters mounted on the machine adjacent to the gas supply bottles.
 8. A road planing machine according to claim 7 including duct means extending between said heating unit and said gas supply bottles and having an outlet directed towards said gas supply bottles to direct hot air from the heating unit on to the gas supply bottles to pre-heat said bottles.
 9. A road planing machine according to claim 3 including duct means extending over said heating unit and having an outlet disposed at the forward end of said heating unit relative to the forward direction of movement of the machine in use, and fan means arranged to deliver air from said heating unit through said duct means to said outlet, said outlet being directed downwardly so as to direct said air on to the road surface ahead of the heating unit to pre-heat said surface.
 10. A road planing machine according to claim 3 including means arranged between said frame and said heating unit for raising said heating unit clear of the ground for transport purposes.
 11. A road planing machine to claim toclaim 3 including drive means operable to effect forward movement of the machine, means operable to interrupt said drive means to stop movement of the machine, sensing apparatus coupled to said heating unit and operable to give a signal in the event of the heat output from said unit falling below a pre-determined level, and control means operable in response to said signal to actuate said means for interrupting the drive means.
 12. A road planing machine according to claim 1 including rearwardly converging guide members mounted between said cutter assembly and said elevator to draw together material removed from the road surface by the cutters for lifting by said elevator.
 13. A road planing machine according to claim 12 wherein said guide members and said elevator are adjustably mounted for movement to a position clear of the road surface for transport purposes.
 14. A road planing machine according to claim 1 including a hydraulic drive mechanism operatively connectable to said Ground-engageing wheels of the machine to provide infinitely variable low speed creeping movement of the machine during operation.
 15. A road planing machine according to claim 14 including in addition a mechanical drive mounted on said frame and operatively connectable to said ground-engaging wheels to propel the machine when not in use, and control means operable to selectively couple either said hydraulic or said mechanical drive to the ground-engaging wheels of the machine as required.
 16. A road planing machine according to claim 14 including means for disengaging said hydraulic drive mechanism in the event of any cutter of the cutter assembly striking an obstruction.
 17. A road planing machine according to claim 1 wherein said cutter assembly includes more than one series of transversely arranged cutter wheels, the successive series being disposed at different cutting depths relative to the road surface.
 18. A road planing machine according to claim 1 including a main control station movably mounted on the machine between alternative operating positions at opposite sides of the machine.
 19. A road planing machine according to claim 1 including a main control station slidably mounted on a track extending transversely of the machine.
 20. A road planing machine according to claim 1 including a main control station, and extension controls coupled to said main control station and disposed at a low level at one side of the machine.
 21. A road planing machine according to claim 1 including an individual fluid-operated motor operatively coupled to each of said cutter wheels and hydraulic fluid supply and return pipes connecting each of said motors to a common pressure fluid source mounted on the machine.
 22. A road planing machine having a frame provided with ground-engaging wheels, a cutter assembly mounted on the frame, a heating unit mounted on the frame forwardly of the cutter assembly relative to the forward direction of movment of the machine in use, duct means extending over said heating unit and having an outlet disposed at the forward end of the heating unit, and fan means arranged to deliver air through said duct means to said outlet, said outlet being directed downwardly so as to direct said air on to the road surface ahead of the heating unit to pre-heat said surface.
 23. A road planing machine according to claim 22 wherein said fan means is arranged to draw in said air from said heating unit. 